Usually yes, because they tend to be the higher end and luxury cruises - and they have higher standards for their crew and so pay a premium wage (and generally treat them better with respect to time and benefits).

Yes, there really is no tipping expected, and (after 2 such cruises) have never felt that anyone looked as if they were expecting me to give them any cash. It is SO different than on other lines, where I found staff to be overly solicitous and almost oily in the way they tried to ensure I would remember who they were. On my last cruise, I did want to give something extra to my table's chief waiter, who I thought was extraordinary, so I went to the service desk where I could direct some of my on-board account to be forwarded to her as a tip.